Use the converter as a mathematical normalization between scales, not as an official credential-evaluation result. International grade interpretation depends on the education system and receiving institution.
There is no universal GPA conversion
A straight-line 75/100 → 3.0/4.0 calculation can be mathematically neat and academically wrong if the systems use different grade distributions, pass marks or classifications.
Use official or institution-specific methods when provided
If a university, credential evaluator or admissions authority publishes its own conversion table or formula, that method takes priority over a generic calculator.
Keep the original grade visible
Applications should normally preserve the original transcript scale. Use the converted number for planning and comparison only unless the receiving organisation explicitly instructs you to report a converted result.